During the Great War, the Admiralty initiated a system of intelligence gathering with regard to U-boat attacks, and the armament, equipment and types of U-boat involved. Standardised questionnaires were produced in English and French (Form S.A.), completed copies of which survive bound into volumes by the Intelligence Division of the Admiralty, London. These are now held at The National Archives at Kew. This report describes the attack on the GLENART CASTLE.

Source:
ADM 137/3982. Enemy submarines: particulars of attacks on merchant vessels in home waters. 1- 9 March 1917. ADM - Records of the Admiralty, Naval Forces, Royal Marines, Coastguard, and related bodies. The National Archives, Kew. n.p.